Allow adding domains to block list during an active block

[guifry]

Summary

Problem: Once a block is active, I can’t add new distracting domains.
Solution: Allow additive updates (only adding, not removing/editing) to the block list during an active block.

Is your feature request related to a problem? Please describe.

If I forget to add a website before starting a block, I’m stuck with access to it until the timer ends. This undermines the whole purpose of using SelfControl, since I can still reach distracting sites during the session.

Describe the solution you'd like

Enable adding new domains to the block list while a block is active. These newly added sites should immediately be blocked for the remainder of the session. Existing entries must stay locked, so the integrity of the block is preserved.

[cstigler]

@guifry have you tried the "Add to Blocklist" button on the timer window?

[bzmarkovits]

It already exists.